Henry a



(No Model.)

H. A. SEYMOUR.

ELECTRIC ARG LAMP.

Patented NOV.3,1896.

UNITED STATES PATENT OFFICE.

IIENRY A. SEYMOUR, OF VASI'IINGTON, DISTRICT OF COLUMBIA.

ELECTRIC-ARC LAM P.

SPECIFICATION forming part of Letters Patent No. 570,823, dated November3, 1896.

Application filed Iuly 1,1896. Serial No. 597,752. (No model To all whomit may concern;

Be it known that I, HENRY A. SEYMOUR, of lVashington, in the District ofColumbia, have invented certain new and useful Improvements inArc-Lamps; and I do hereby declare the following to be a full, clear,and exact description of the invention, suoli as will enable othersskilled in the art to which it appertains to make and use the same.

My invention relates to an improvement in arc-lamps, and has specialrelation to that type of lamps which are operated by alternatingcurrents.

I'Ieretofore many attempts have been made to produce arc-lamps capableof being operated by an alternating current, and while lamps of thischaracter have been constructed which would operate with indifferentsuccess when burning a short are, no one has yet succeeded in producinga practically efficient and satisfactory alternating arc-lamp capable ofestablishing and maintaining a long are within an are-inelosing globe.

The establishment of an are between the carbons of analternating-current are-lamp necessitates the heating of the adjacentends of the carbons to such a degree as will result in the formation ofa bridge of conducting vapor or gas across the gap or space between themwhen separated to preserve intact the circuit and insure the continuedflow of eurrent from one carbon to the other. Excepting some provisionbe made for heating the adjacent ends of the carbons, when current isfirst passed through such a lamp the carbons and regulating mechanismwill violently chatter for a considerable length of time before it ispossible to establish and maintain even a short are. This action is dueto the fact that when a rapidly-alternating current is passed throughthe cold carbons the current falls to zero so rapidly that the carbonswill not be maintained separated for a sufficient length of time toinsure their being heated to such a degree as will result in theformation of a bridge of conducting vapor across the gap between them,which, as has been stated, is essential to the maintenance of apersisting arc. Hence the minute are that is formed between the coldcarbons is established and broken in rapid succession, with the resultthat the electromagn et ofthe regulating mechanism is rapidly energizedand de'energized, thereby causing a rapid and violent chattering of thecarbons and regulating mechanism, which continues until the ends of thecarbons have finally become sufficiently heated to insure the formationof a conducting-bridge of carbon vapor or gas across the space or gapbetween them, and then and not until then is a persisting areestablished.

The operation of alternating arc-lamps as .heretofore constructed hasbeen attended by a constant hissing of the are and buzzing of theregulating mechanism, which has proved so annoying and. objectionablethat such lamps have gone into very limited use.

Attempts have been made to obviate the difficulties above set forth byso constructing the regulating mechanism that it would operate toseparate the feeding carbon from the non-feeding carbon very slowly andgradually, and thereby insure the establishment of a persistent arebetween them without the accompanying chattering of the carbons and ofthe regulating mechanism; but lamps so constructed proved inefficientand defective in their operation, even when burning a short are, for tworeasons: First, in providing the regulating mechanism with means forretarding the initial separating movement of the feeding carbon from thenon-feeding carbon, it rendered the action of the regulating meehanismin adjusting and feeding the carbon so slow and sluggish as to render itincapable of adjusting and feeding the carbon with that delicacy andsensitiveness which are necessary to the maintenance of a steady andreliable persisting arc, and, second, by imposing upon the regulatingmechanism associated with the feeding carbon the duty of separating itfrom the non-feeding carbon and of drawing a long arc the relationbetween the helix and core of the solenoid was so varied as rendered itimpossible to insure the prompt and sensitive adjustment and feed of thefeeding carbon.

The object of my invention is to provide an arc-lamp of suchconstruction that the function of slowly separating the carbons andgradually drawing a long are shall be performed by mechanism associatedwith and acting upon vthe lower and non-feeding earbon, while all thefunctionsnecessary to the IOS) regulation and feeding of the carbonsshall be performed by mechanism associated with and acting upon thefeeding carbon.

lVith this end in view my invent-ion consists in an arc-lamp comprisingcertain features of construction and combinations of parts, as will behereinafter described, and pointed out in the claims.

In the accompanying drawings, Figure l is a view, partly in verticalsection and partly in side elevation, of an arc-lamp embodying myinvention; and Figs. 2 and 8 are detailed views of the dash-pot.

A is the lam p-tloor, from which the bracket B is suspended andinsulated. The bracket is composed of the long arm u, short arm a', andconnecting-ring c?, the latter serving the double purpose ofstrengthening the bracketframe and guiding the upper end of thearcinclosing` globe N. This bracket may be cast in a single piece ormaybe made in separate pieces fastened together in any desired manner.

D is a solenoid secured to the lower end of the bracket. The core d ofthe solenoid has mounted thereon a carbon-holding socket d', which isinsulated from the core by the insulating-piece d2. Spiral spring D'serves to uphold the core and carbon F/. IIeliX Eis composed ofcomparatively thick wire, one of its ends being attached to socket d bythe liexible conductor e, while its opposite end is electricallyconnected at c with the bracketarm a. To the under side of the solenoidis secured a dash-pot G, which is shown in detail in Figs. 2 an d 3.Piston-rodf of the dashpot is connected at one end to the core and atits opposite end to the piston II, which latter is provided with anadjustable screw-valve g, by means of which the speed of the pistonthroughout its downward stroke may be retarded and cheeked to anydesired extent. A number of holes g/ are formed through the piston, andthese holes are closed by an annular valve G, which seats against theunder side of the piston and is held against its seat by means of thestems h and spiral springs 7L'. By means of this construction of pistonthe lower carbon maybe retarded in its downward movement and bepermitted a quick and prompt upward movement.

I is a coarse-wire solenoid supported upon brackets t' or in any otherdesired manner. I is a hollow core provided at its lower ends withoutwardly-projecting arms 2', which are perforated at their outer endsfor the reception of the vertical guide rods Spiral springs encircleguide-rods t2 and thereby uphold the hollow core and parts connectedtherewith. The tension of the spiral springs may be regulated by theset-nuts t4. IVithin the hollow core is located the tubular carbon rodor holder J, which passes through an annular valve j, which rests uponthe lampiioor and is free to move laterally thereon. The valve serves toprevent the passage of gases from the globe into the casing contain.-

in g the regulating mechanism. K is a ringclamp which encircles thecarbon-holder and is provided with an annular groove 7c, in whichengages the iinger of the litter 7d, the latter being attached to thehollow core. A piston L is placed within the tubular carbon-holder andis supported by the rod L, which is secured at its upper end to thelamp-casing M.

N is an arc-inclosing globe supported at its lower end in the socket Nand held in place by the set-screws N2. Suitable packing u may beemployed to insure a tight joint around the bottom of the globe. Theiloor of the globe-socket is provided with an opening in which the cored snugly its and through which it is free to move. The upper end of thearc-inclosing globe extends through the ring d? of the bracket and isthereby held in place. A cover O is applied to the top ofthe globe andis provided with an opening through which the upper carbon is fed.

The outer globe is furnished with a metal binding at its upper end, withwhich is connected a strip I), which engages and slides upon the bracketwhen the globe is lowered, thereby permitting the latter to besuspended, as indicated by dotted lines, when the lamp is being trimmed.

The operation of the lamp is as follows: Current enters the lamp throughbindingpost Q and from thence llows through the helix of the coarse-wiresolenoid tothe lamptloor, from which it passes through the carbons F F,helix o'l solenoidI) to bracket-arm d, and upwardly to binding-post Q'and from thence to line. On the passage of current through the lamp bothsolenoids I and D will be energized, but owing to the fact that anadjustable stop q is provided for restricting the upward movement of thering-clamp solenoid Iwill serve to tilt the ring-clamp and cause it toclutch the carbon-holder, and possibly lift it an almost inappreciabledistance, while at the same time solenoid D will pull down the lowercarbon. The downward movement of the lower carb on is rendered so slowand gradual by the retarding etlect of the dash-pot that the arc isslowly drawn to any desired length without danger of its extinction. Inshort, the separation of the two carbons is rendered so slow and gradualthat their adjacent ends will be heated to a sufcient degree to insurethe formation of a conductingbridge of carbon vapor across the gapbetween them, which will serve to maintain the integrity of the circuitthrough the lamp and hence prevent the extinguishment of the arc. As thecarbons continue to burn, the arc grows longer and its resistanceincreases,with the result that the solenoid I becomes weaker and allowsits core to descend and feed the carbon through the ring-clamp until bythe shortening of the arc and the consequent decrease of its resistancethe solenoid is rendered suiiiciently strong to again lift the core andcause the ring-clamp to grip and raise the carbon-holder and feedingcarbon.

IOO

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In this manner the feeding carbon is adjusted and fed until both carbonshave been consumed.

Each one of the solenoids is provided with a closed diamagneticconductor s, consisting of a closed tube of copper or brass, which maybelocated either inside or outside of the helix, and which serves tosuppress the eX- tra current generated in the helices when analternating current is employed in operating the lamp and thus preventthe very slight but annoying vibrations of the regulating mechanism andalso the hissing of the arc when the lamp is burning.

In the event the arc should be extinguished the lower carbon will risequickly and insure its prompt restablishment.

"While I have described the lamp as being specially adapted for use withan alternating current, it is evident that it is Well adapted to beoperated by a straight current, and in the event that it is desired toembody the invention in a series lamp a shunt-solenoid might beassociated with the coarse-wire solenoid andform therewith adifferential regulator.

Having fully described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

l. In an arc-lamp the combination with its upper and feeding carbon, andregulating mechanism comprising a coarse-wire magnet included in serieswith the arc, for raising and lowering and feeding the upper carbon, ofthe lower and non-feeding carbon and a magnet and dash-pot associatedtherewith and constructed and adapted to slowly and gradually separatethe lower carbon from the upper carbon when lthe lamp is switched intocircuit and thereby draw the arc to any desired length, and to maintainthe lower carbon at the limit of its downward movement throughout thenormal operation of the lamp in burning its carbons, substantially asset forth.

2. In an are-lamp the combination with its upper and feeding carbon andregulating mechanism comprising a magnet in series with the arc, and afriction-clutch, said parts being constructed to grip and uphold thecarbon-holder when the lamp is switched into circuit, of the lower andnon-feeding carbon and a magnet and dash-pot associated therewith andconstructed and adapted to slowly and gradually separate the lowercarbon from the upper carbon and thereby slowly draw the arc to anydesired length and to maintain the lower carbon at the limit of itsdownward movement throughout the normal operation of the lamp in burningits carbons.

3. In an arc-lamp the combination with its carbons, a solenoid and adash-pot for gradually and slowly separating the non-feeding carbon fromthe feeding carbon, of an arcinclosing globe mounted on a supportprovided with an opening in which the core of said solenoid snugly iitsand through which it is free to move, substantially as set forth.

at. In an arc-lamp, the combination with a depending frame comprising along arm and a short arm, and a guide-ring connecting them, of anarc-inclosing globe supported at its lower end in a socket, and havingits upper end maintained against lateral displacement by saidguide-ring7 substantially as set forth.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

HENRY A. SEYMOUR.

lVitnesses S. G. NOTTINGHAM, G. F. DowNING.

